Brake-shoe



v (No' Model.)

' W. W. WHITOOMB.

BRAKE SHOE.

Patented June 16, 1896,

UNITED STATES PATENT OFFICE.

\VILLIAM WV. WHITCOMB, BROOKLINE, MASSACHUSETTS, ASSIGNOR TO THECOMPOSITE BRAKE-SHOE COMPANY, OF BOSTON, MASSACHUSETTS.

BRAKE-SHOE.

SPECIFICATION forming part of Letters Patent No. 562,346, dated June 16,1896.

Application filed April 10, 1896. Serial No. 586,955. (No model.)

To ctZZ whom it may concern:

Be it known that I, WILLIAM XV. NVHIT- COMB, residing in Brookline, inthe county of Norfolk and State of Massachusetts, have invented anImprovement in Brake-Shoes, of which the following description,inconnection with the accompanying drawings, is a specification, likeletters on the drawings representing like parts.

This invention relates to brake-shoes, and has for its object toincrease the efliciency of the same, as will be hereinafter described.

The invention is more particularly an improvement upon that class ofbrake-shoes having a longitudinal groove or channel of a widthsubstantially equal to the width of the tread of the rail upon which thecar-wheel runs.

Brake-shoes of the class just described are provided with thelongitudinal groove re ferred to, so that the portion of the wheel wornby contact with the tread of the rail may not be subjected to extra wearby the brake-shoe, which action, if permitted, would materially shortenthe life of the car-wheel. These brake-shoes are efficientfor thepurpose specified, but this efliciency in this respect is obtained at asacrifice to the braking efficiency of the shoe, by reason of the factthat a substantially large amount of braking surface is absent from thebrake-shoe.

It is the object of this invention to improve brake-shoes of the classreferred to, whereby increased braking effect may be obtained withoutwearing effect of the brake-shoe upon that part of the wheel worn by therail, and I accomplish my invention by providing the longitudinalgroove, which is preferably enlar d at its rear portion, with abrakingsurface of softer material than the main portion of thebrake-shoe, and preferably wooden sections or blocks firmly secured orlocked in the said longitudinal groove, which softer material acts onthe portion of the wheel worn by the rail and increases the brakingefficiency of the shoe without detrimental wearing action on the wheel.

These and other features of this invention will be pointed out'in theclaims at the end of this specification.

Figure]. is a plan view of a car-wheel with a brake-shoe embodying thisinvention applied thereto and shown in section; Fig. 2, a side elevationof the brake-shoe shown in Fig. 1 looking toward the right; Fig. 3, afront elevation'of the brake-shoe shown in Fig. 2 looking toward theleft; Fig. 4, an elevation of the rear or back side of the brake-shoeshown in Fig. 2 looking toward the right; Figs. 5 and 6, frontelevations of modified forms of brake-shoes embodying this invention;and 7, a sectional detail to be referred to, the section being taken onthe line 7 7, Fig. 6.

Referring to Fig. 1, A represents a carwheel having the flange a andwhich may be of any suitable or usual construction, such as now commonlyused on railways. The car-wheel A has cooperating with it a brakeshoe A,which may be made of any suitable or usual metal, such as cast iron orsteel, and which consists of a body portion a, provided withalongitudinal groove, channel, or slot a of a width at the face a of theshoe substantially equal to the width of the rail upon which thecar-wheel runs and not herein shown, the said groove or channel beingpreferably enlarged at or near its rear portion or end, as at of, whichenlargement is herein shown as dovetail in form and preferably extendsthe entire length of the depth of the groove or channel a The groove orchannel a is less than the thickness of the shoe, so as to leave a solidback or bottom for the channel integral with the shoe, and, inaccordance with this invention, the said groove or channel receiveswithin it a body or filling of softer material than the metal of whichthe shoe is composed, and the saidbody or filling may and preferablywill be composed of blocks or sections Z) of wood or other non-metallicZ) are driven or otherwise forced into the groove or channel m asrepresented in Fig. 1.

The filling or inserted braking-surface is preferably made in sectionsand inserted into the groove or channel a so as to leave airspaces 19between adjacent sections or blocks, and the back wall of the channel orgroove a is preferably provided with one or more holes or openings bcommunicating with the airspaces 19 for the passage of dust or otherparticles as the shoe is worn, and the blocks or sections 7) may beprovided with longitudinal holes or openings 5 in line with each otherfor the circulation of air longitudinally through the shoe, whichair-circulation serves to convey away the heat-currents and diminishesthe heating of the shoe.

The back wall of the slot a may also be provided, if desired, withadditional holes or openings b (see Fig. 4:) between the holes oropenings 17 to still further ventilate the shoe and thereby stillfurther diminish the heating of the shoe.

The brake-shoe shown in Figs. 1 to 4:, inclusive, is constructed forengagement with the flange a of the wheel, and is provided with a groove19 to embrace the flange CL, and this groove b may, if desired, beprovided with one or more wooden or other plugs or blocks Z9 insertedinto and secured in suitable sockets in the walls of said groove. So,also, the wheel engaging face a may be provided, if desired, with woodenor other plugs Z9 By reference to Fig. 1, it will be seen that theportion of the wheel A which runs upon and is worn by the rail isengaged by the wooden sections or blocks when the brake is set, and byreason of the blocks or sections being made of softer material than thewheel 1 and of softer material than the body of the brake-shoe the wheelis not worn by the said 1: sections or blocks, but the adhesion of the:shoe to the wheel is increased and conse-: quently the brakingefficiency of the shoe is increased. I may prefer to make the softerbraking material, which fills the groove or slot of wood in the form ofsections or blocks, as herein shown, and to lock the same in the saidgroove or channel, but I do not desire to limit my invention in thisrespect, as a single block d, of wood or non-metallic or othercomposition or metal softer than the bodyof the shoe, may be inserted orotherwise put into the said slot, channel, orgroove, as represented inFig. 6. When composition is used, the locking device or wedge Z) may bedispensed with and the enlargement or recess in the back of the slot orchannel a depended upon to retain the braking material in the said slotor channel. So, also, I prefer to ventilate the brake-shoe substantiallyas described, but the ventilating-openings may be omitted withoutdetracting from the action of the braking material in the slot orchannel a 7 In Figs. 5 and 6 I have shown my invention as embodied in abrake-shoe which is not constructed for engagement with the flange ofthe wheel.

In operation as the harder braking-surface a of the shoe engages theportion of the wheel not worn by the rail and wears away the wheel, thefilling or body of softer material is being worn by the portion of thewheel which makes contact with the rail, and, as it is worn, the saidbody or filling adapts itself to the form of the portion of the wheelworn by the rail and consequently maintains a maximum braking-surface incontact with the said wheel.

I claim- 1. A brake-shoe consisting of a body por tion provided with alongitudinal slot, channel or groove of a width substantially equal tothe width of that portion of the car-wheel worn by the rail and of adepth less than the thickness of the shoe to leave a solid bottom forthe slot integral with the shoe, a body of softer material than the shoein the said slot, channel or groove and adapted to engage that portionof the wheel worn by the rail to form a braking-surface therefor, andmeans within the said slot for retaining the body of softer materialtherein, substantially as and for the purpose specified.

2. A brake-shoe consisting of a body portion provided with alongitudinal slot or channel of a width substantially equal to the widthof that portion of the car-wheel worn by the rail and provided with anenlargement within it and having a solid bottom integral with the shoe,and a body of softer material inserted into said slot or channel andextended into the enlargement thereof, and adapted to engage thatportion of the wheel worn by the rail to form a braking-surfacetherefor, substantially as described.

3. A brake-shoe consisting of a body portion provided with alongitudinal slot, channel or groove of a width substantially equal tothe width of that portion of the car-wheel worn by the rail and providedwith a solid bottom integral with the shoe, and blocks or sections ofnon-metallic material inserted into .said slot, and means to lock saidblocks or space communicating with the opening in the back wall of thechannel or slot, substantially as and for the purpose specified.

5. A brake-shoe consisting of a body portion provided with alongitudinal slot, channel or groove of a width substantially equal tothe width of that portion of the car-Wheel In testimony whereof I havesigned my Worn by the rail, and a body of softer matename to thisspecification in the presence of rial inserted into said slot to form abrakingtWo subscribing Witnesses.

surface for the portion of the Wheel Worn by WILLIAM W. WHITCOMB. 5 therail and provided With a 10n gitudinal open- Witness es ing forming anair-circulating passage, sub- J AS. H. CHURCHILL,

stantially as and for the purpose specified. J. MURPHY.

